//
//  ViewController.swift
//  swift3.0 遍历构造函数
//
//  Created by 龚昕炜 on 16/7/27.
//  Copyright © 2016年 龚昕炜. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        DispatchQueue.global().async { 
            
            DispatchQueue.main.async(execute: { 
                
            })
            
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

